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Appendix A: Methodology and Technical Notes

Common Core of Data survey system.

The Common Core of Data (CCD) survey system has nonfiscal and fiscal components and the Teacher Compensation Survey (TCS). The State Nonfiscal Survey of Public Elementary/Secondary Education, the Local Education Agency Universe Survey, and the Public Elementary/Secondary School Universe Survey are the nonfiscal components, while the School District Finance Survey (F-33) and the National Public Education Financial Survey (NPEFS) are the fiscal components. The TCS is also a part of the CCD survey system.2 These surveys are reported annually by state education agencies (SEAs). Participation in the CCD is voluntary.

Data for CCD nonfiscal surveys are collected from SEAs through the U.S. Department of Education’s EDFacts system. Data for CCD fiscal surveys are collected from SEAs by the U.S. Census Bureau, which acts as the collection agent for NCES. The data are collected through an online data collection site. They are then processed, edited, and verified by the Census Bureau, the National Center for Education Statistics (NCES), and the Education Statistics Services Institute (ESSI) of the American Institutes for Research (AIR). The fiscal year 2008 (FY 08) NPEFS collection opened on February 16, 2009 and closed on September 8, 2009. All states, the District of Columbia, Puerto Rico, and four other participating jurisdictions reported in the FY 08 NPEFS collection.

Data quality.

Staff at NCES, the Census Bureau, and ESSI collaborate to edit all CCD data submissions and ask state CCD coordinators to correct or confirm any numbers that appear out of range when compared with other states’ data or with the state’s reports in previous years. If no explanation for anomalous data is provided by the state, NCES will change the data value. For example, NCES will replace a reported total with the sum of detail in cases where the sum of detail exceeds a reported total. NCES will also change a value to “not available” if data values are not plausible (e.g., if the number of students increases tenfold from the prior year to the current year while the number of teachers remains unchanged from the prior year, NCES will set the current year value for teachers to “not available”).

Missing data.

Not all states collect and report all of the data items requested in the CCD surveys. NCES imputes (replaces a nonresponse with a plausible value) for some missing items in NPEFS. Precise information about the extent of missing data is included in the documentation for the NPEFS FY 08 file.

Imputed and adjusted data.

NCES imputes and adjusts some reported values in the NPEFS to create data files that more accurately reflect finance data and to improve comparability among states. Imputations and adjustments are performed on data from the 50 states and the District of Columbia only. A limited amount of data for Guam, the Commonwealth of the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands were reallocated across functions.

  • Imputations correct cases in which a value is not reported at all, indicating that subtotals for the item are underreported. An imputation by NCES assigns a value to the missing item, and the subtotals containing this item are increased by the amount of the imputation. The same method is used for imputing revenues and expenditures. Revenues are imputed based on total revenues in reporting states, and expenditures are imputed based on total expenditures in reporting states.
  • Adjustments correct cases in which a value reported for one item contains a value for one or more additional items not reported elsewhere. For example, a state might not differentiate between instructional support staff and student support staff, reporting “missing” for student support staff salaries and a value for instructional support staff salaries that includes both items. NCES would adjust these two responses by reducing the amount reported for instructional support staff salaries and adding that amount to student support staff salaries. The total for salaries and total expenditures would not be affected by this adjustment.3

All imputed values in the tables in this report are noted, and imputed values are never used in the imputation of another value. Totals and subtotals in tables are noted if one or more items in the total or subtotal are imputed or adjusted. In some instances, state values are affected by the redistribution of reported values to correct for missing data items. 

Beginning with the FY 06 file, NCES notes values that have been affected by the distribution of state direct support for and on behalf of school districts. This results in many more items having noted data than in previous reports. States that report their direct support expenditures with their detailed finance data are not noted, since no redistribution was required.

Respondents for the NPEFS were asked to review student membership data from the CCD State Nonfiscal Survey of Public Elementary/Secondary Education to make sure that the membership data were for programs whose revenues and expenditures are reported on NPEFS. Six states (Iowa, Missouri, Montana, Nebraska, North Carolina, and Wyoming) indicated that prekindergarten programs were not included in the NPEFS data, and so counts of these students were subtracted from the student membership data reported on the State Nonfiscal Survey of Public Elementary/Secondary Education for use on the NPEFS. Wisconsin does not include finance data for charter schools in the NPEFS data they report. Student membership for Wisconsin was adjusted to exclude charter school membership. The membership for Wisconsin was derived from the CCD School District Finance Survey.



National totals reported in the tables are limited to the 50 states and the District of Columbia. They do not include data from Puerto Rico or the four other jurisdictions of American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, or the U.S. Virgin Islands.

Current Expenditures.

Researchers generally use current expenditures instead of total expenditures when comparing education spending between states or across time because current expenditures exclude expenditures for capital outlay, which tend to have dramatic increases and decreases from year to year. Also, the current expenditures commonly reported are for public elementary and secondary education only. Many school districts also support community services, adult education, private education, and other programs, which are included in total expenditures. These programs and the extent to which they are funded by school districts vary greatly both across and within states.

Comparability of fiscal data across states.

Because the District of Columbia is a single urban district, it is often an outlier in comparisons of revenues and expenditures, with larger revenues and expenditures per student than most states have. Similarly, Hawaii is a single school district and funds public education primarily through state taxes. Because of this, Hawaii’s data may pose similar problems of comparability.

Inflation-adjusted data.

Data in figure 2 in this report have been adjusted to FY 08 dollars to account for inflation using the Consumer Price Index (CPI). The CPI is published by the U.S. Labor Department, Bureau of Labor Statistics. This price index measures the average change in inflation of a fixed market basket of goods and services purchased by consumers.

Fiscal years.

The fiscal year begins on July 1 and ends on June 30 for most states. The fiscal year for Alabama runs from October 1 through September 30, and the fiscal year for Nebraska and Texas runs from September 1 through August 31. The NPEFS data are not adjusted to conform to a uniform fiscal year across states.



2 The first Pilot Teacher Compensation Survey was launched by NCES in 2007 collecting school year 200506 data.
3 For more information on imputed and adjusted data, see Ave and Honegger (2010).